mtd: rawnand: Stop using nand_release()

This helper is not very useful and very often people get confused:
they use nand_release() instead of nand_cleanup().

Now that all drivers have been converted to do not use nand_release()
anymore, let's remove this helper.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/linux-mtd/20200519130035.1883-63-miquel.raynal@bootlin.com

Documentation/driver-api/mtdnand.rst

@@ -276,8 +276,10 @@ unregisters the partitions in the MTD layer.
     #ifdef MODULE
     static void __exit board_cleanup (void)
     {
-        /* Release resources, unregister device */
-        nand_release (mtd_to_nand(board_mtd));
+        /* Unregister device */
+        WARN_ON(mtd_device_unregister(board_mtd));
+        /* Release resources */
+        nand_cleanup(mtd_to_nand(board_mtd));
 
         /* unmap physical address */
         iounmap(baseaddr);

drivers/mtd/nand/raw/nand_base.c

@@ -6178,18 +6178,6 @@ void nand_cleanup(struct nand_chip *chip)
 
 EXPORT_SYMBOL_GPL(nand_cleanup);
 
-/**
- * nand_release - [NAND Interface] Unregister the MTD device and free resources
- *		  held by the NAND device
- * @chip: NAND chip object
- */
-void nand_release(struct nand_chip *chip)
-{
-	mtd_device_unregister(nand_to_mtd(chip));
-	nand_cleanup(chip);
-}
-EXPORT_SYMBOL_GPL(nand_release);
-
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");

include/linux/mtd/bbm.h

@@ -98,7 +98,7 @@ struct nand_bbt_descr {
 
 /*
  * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
- * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
+ * was allocated dynamicaly and must be freed in nand_cleanup(). Has no meaning
  * in nand_chip.bbt_options.
  */
 #define NAND_BBT_DYNAMICSTRUCT	0x80000000

include/linux/mtd/rawnand.h

@@ -1398,8 +1398,6 @@ void nand_wait_ready(struct nand_chip *chip);
  * sucessful nand_scan().
  */
 void nand_cleanup(struct nand_chip *chip);
-/* Unregister the MTD device and calls nand_cleanup() */
-void nand_release(struct nand_chip *chip);
 
 /*
  * External helper for controller drivers that have to implement the WAITRDY